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7/16/2015 | 4 MINUTE READ

Seven New Technologies Debut at W&H Open House

Film Extrusion
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Among them at the two-day event in Germany is a new method to drastically reduce product-changeover times.

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Windmoeller & Hoelscher (W&H) dubbed its triennial open house in Lengerich, Germany, “Packaging 4.0.” It could have just as easily been named Packaging 7.0, as the builder rolled out that many new technologies in blown and cast film during the program.

The two-day event, held June 10-11, drew more than 1000 attendees from more than 60 countries. W&H, whose U.S. operation is in Lincoln, R.I., gave them plenty to see, running six different film extrusion lines (five of them of the blown film variety), each of which contained at least one piece of technology never shown before.

Perhaps the most novel of these technologies was displayed on a three-layer Varex II blown-film line (which debuted at K 2013) producing lamination film. Called Turboclean, this new system is said to reduce the time it takes between product changeovers from 30 min to an astounding two min. It will be available on all W&H Varex II lines and figures to be particularly appealing to processors in North America, where film lines dedicated to running a single product are rare.

Product changeovers utilizing Turboclean occur at a speed comparable to a NASCAR pit stop, notes Andrew Wheeler, president of W&H Corp.  To activate Turboclean, the operator initializes specially designed software integrated in W&H’s ProControl TS operator console to stop drawing in materials currently being run. Old materials are then drained from the system at high speeds using special pneumatics. Bins located below each feeder capture previously run material. All hardware components, including hoppers and hoses, are cleaned automatically before new materials are feed into the system.

On this particular line at the open house, W&H switched back and forth between blue- and red-colored films, with the complete changeover taking about 2 min. All told, seven different material components were switched back and forth. The system is designed to work with vacuum loaders furnished by Mann + Hummel (mann-hummel.com).

What’s more, the line was equipped with another feature not previously reported. Called Easy Change, this technology gives operators the ability to make scheduled adjustments to extruder RPMs, air-ring/IBC air volume, the bubble-sizing cage and collapsing frame, and winding speed. This allows operators to make pre-programmed product-format changes—such as to film width, thickness and layer ratio—in as little as 4 min as opposed to the usual 15-20 min. On this three-layer lamination-film line, film width at the winder was switched between 43.3 in. and 60.6 in.

A second, three-layer Varex II line W&H—producing diaper-backsheet film—featured a third new piece of technology: An inline machine-direction orientation (MDO) unit engineered to minimize neck-in and the resulting edge trim. Called the Optifil P-MDO, the device is designed to work with W&H’s Optifil P auto-gauging systems (either die or air-ring based). The technology has been designed to “trick” the auto-gauge system—the thickness profile is adjusted to reduce the amount of edge trim caused by the neck-in effect during the subsequent stretching process. When the film is stretched, the neck-in is evened out uniformly across the film width, reducing the amount that needs to be trimmed and thus improving yield.

A third Varex II blown-film line showcased W&H’s fourth breakthrough. It ran nine-layer, reclosable film for lidding. This film featured an outer layer made from a pressure-sensitive adhesive (PSA) material furnished by Bostik (bostik-us.com). PSA is difficult to extrude, processes at low temperatures, and is generally run on cast film lines, states Wheeler. But W&H ran the material on a water-cooled extruder with a specially designed screw. The breakthrough was overcoming the problems associated with running this particular material with nylon, which melts at much higher temperatures. 

W&H’s fifth new innovation was displayed on its Aquarex line, which is the machine builder’s “upside down” water-quenching blown-film system. This line now features what’s believed to be the first-ever adjustable sizing ring, or calibrator, meaning that film processors no longer need to swap-out calibrators to make changes in product sizes. The adjustable calibrator has a working range of 20 in., about the same as you would find on a conventional air-cooled blown film line. 

“The trick is to make the adjustment without running water escaping, and you can’t use an iris design because the overlapping plates will create lines on the film,” Wheeler notes. He explains that ring adjustments are made by a series of stepper motors placed around the circumference of the calibrator. 

The line also featured an automatic air ring. At the open house, the Aquarex line produced asymetric, seven-layer barrier film consisting of nylon, EVOH, tie layers, and LLDPE. The market for this technology is still unfolding worldwide, W&H notes. 

W&H believes water-cooled blown film can potentially supplant certain applications currently held by cast film. Blown film cooled by water has optical properties about equal to cast film, Wheeler explains, provides better transverse-direction properties, and allows more cost-efficient production of narrow widths. Medical is another possibility, notably IV bags currently made out of PVC. 

W&H sixth new product was a five-layer  version of its Optimex blown film series, which previously was available up to three layers.

Cast-film processors weren’t left out during the two-day affair. W&H ran a seven-layer cast line for stretch with an enhanced Filmatic PS winder. The seventh innovation displayed at the open house, the winder can now handle film at a thickness of 8 microns at speeds above 600 m/min (1969 ft/min). The amount of air entrapped in the winding gap is now controlled by an adjustable wrap angle of the film on the contact roll. In combination with precise web tension control, this feature is said to be particularly important when winding thin and elastic film at high speeds.